2:12 pitch dormer

[gary the cobra]

Is it o k to use 3 tab composition roofing on a dormer that has a pitch of 2:12 ?
I don't want to go too flat so it won't drain off properly. This is in the rainy Pacific Northwest.

 

[matt_i]

I would do it but after I applied peel & stick ice+water shield to the entire dormer(s).

 

[Ed Devinney]

We used metal on the 2/12 portion of our roof. Shingles might work, but in the PNW do you want to take the risk?

 

[MoonRise]

GAF (shingle company, in case you didn't know) says it's OK, IF you double-layer the roof deck protection.

https://www.gaf.com/Warranties_Tech...on_Low_Slopes_2_12_to_4_12_TAB_R_2011_127.pdf


http://www.gaf.com/Roofing/Residential/Products/Roof_Deck_Protection

http://www.gaf.com/Roofing/Commercial/Guide_To_Low_Slope_Roofing_Systems

Or just go and apply the ice-n-water shield peel-n-stick rubber membrane stuff.

http://www.gaf.com/Roofing/Residential/Products/Leak_Barriers/StormGuard

But make sure you have adequate attic ventilation and moisture control both above and from below.

http://www.gaf.com/Other_Documents/...cus_Full_Deck_Coverage_with_Leak_Barriers.pdf

 

[Richard Cranium]

it is very low pitched, If I could get away from doing it, I would.
Also in the PNW.

 

[kbs2244]

No, it is not OK.
Use metal or a steeper pitch.

 

[James-W]

If it were mine I wouldn't do it, I would go with metal roofing. Around here, in the past few years, there have been a lot of people going with metal roofing instead of replacing their old shingles. The new metal roofing looks quite good and it lasts a very long time.

 

[gary the cobra]

O k composition is out for the 2:12 dormer part of he roof. I'll go with a torch down product or metal for the dormer part. It won't exactly match the rest of the comp on the new shop, but it is up fairly high and won't be super visible. It won't leak either. I need to stick with comp for the rest of the roof as it matches my house.Thank you for the great advise.